In the Old Testament, Jacob was one of the twin sons of Isaac and Rebecca, and was born clinging to the heel of his brother Esau. This was a sign from God that they would head two tribes, and that Jacob, the younger twin, would be stronger than Esau, who would serve him.

Jacob became a herdsman and his mother's favourite, Esau a hunter and his father's favourite. One day, faint with hunger, Esau sold his birthright to his brother for food. When they were older, Rebecca contrived that Jacob should receive his father's blessing in Esau's place: she disguised Jacob as his brother so that the old and nearly blind Isaac would mistake the younger for the elder when giving his (irrecovable) blessing. When Esau discovered this, he swore to kill his twin.

Rebecca sent Jacob away to escape his brother's wrath, and to marry one of the daughters of his uncle, Laban, so that he would not have to marry a local Canaanite. On his way he took stones of that place, and put them for his pillows, and lay down in that place to sleep. And he dreamed, and behold a ladder set up on the earth, and the top of it reached to heaven; and behold there were angels of God ascending and descending on it. During the dream God told Jacob that he and his descendants would prosper. On his travels Jacob met Rachel, one of Laban's daughters, as she was bringing her father's flocks to the water. Jacob rolled back the stone that covered the well. Rachel was very beautiful, and Jacob offered to work for Laban for seven years to win her hand. Laban agreed, but when the time came for their wedding, he put his elder daughter Leah in Rachel's place, because the younger sister could not marry before the elder. Jacob still loved Rachel, however, and he offered to work for seven more years so that he might marry her, too; Laban agreed that it would be better to give his daughter to Jacob than to another man. Jacob had many children by both of his wives, and by their handmaids, and after 20 years he resolved to return to Canaan with them all. They left secretly, Rachel taking her father's household idols. Laban pursued, eventually overtaking them, but Rachel kept the idols hdiden by sitting on them. The night before they reached Canaan, Jacob, alone by a brook, wrestled with an angel until daybreak. Unable to throw him, the angel refused to tell his name, but said that Jacob would henceforth be named Israel. Jacob then understood that he had been wrestling with God.
As they approached Canaan, Jacob heard that Esau was coming to meet him with 400 men, so he sent his brother part of his herd in appeasement. When they met, the brothers embraced and wept.

In his old age, Jacob blessed the children of Joseph, his favourite son. He prophesied that in the future his own 12 sons would be the founders of the 12 tribes of Israel.